ABSTRACT
The analysis of piled raft foundations has improved over the last few decades to account for the combined contribution of rafts and piles to provide a more efficient system. A structural cushion separates the piles from the raft in the unconnected piled raft foundation (UCPRF), an economical and efficient system for high-speed rail viaducts. The cushion helps in decouple the superstructure from seismic ground motions, potentially enhancing the resilience of the viaduct during earthquakes. Incorporating geomaterials in the cushion material further helps in attenuating seismic waves and enhance isolation effect. This study performs 3D finite element analysis (FEA) considering the real-time history of seismic motion and non-linear soil-structure interaction using hardening soil with small-strain stiffness (HS small) constitutive model. Key parameters such as lateral displacement, seismic isolation effect, and shear force bending moment of the pier are studied to evaluate the performance of the structure.
